The Democrats gained 20 seats, but Grant's Republican Party retained a commanding majority in the Reconstruction era following the American Civil War, holding onto a firm legitimacy through an association with victory. As more Southern states exited Reconstruction, more Democratic seats appeared in the South. However, Democratic gains in the South were limited, as the Republican power-brokers of Reconstruction held a great deal of influence. The small Conservative Party of Virginia also picked up several seats in Virginia, as it had support among wealthy Southern leaders who wanted to increase the region's power.

Mississippi, Texas, and Virginia were readmitted during this Congress, leaving Congress without vacant State delegations for the first time since 1860. Georgia had been partially readmitted in the previous Congress, but was not initially admitted to the 41st Congress. With Georgia's final readmission in 1870, all former Confederate states were once more represented in Congress.

In 1845, Congress passed a law providing for a uniform nationwide date for choosing Presidential electors. This law did not affect election dates for Congress, which remained within the jurisdiction of State governments, but over time, the States moved their Congressional elections to that date. 1868 was the first year in which the majority of States (20 of 37) held their elections on that date. There were still 9 states which held elections before that date and 4 that held regular elections after that date, in addition to 4 readmitted states that held elections after that date